Before checking for updates or finding the right solution for your problem, you need to know which version of QuickBooks you have.
To find product version and release information:
The product edition and version appear in the title bar, at the top of the product window.
Press F2 to open the Product Information window. Version, edition, and release appear at the top of the window, on the Product line.
Press and hold the CTRL key, and then double-click the QuickBooks icon on your desktop. Continue pressing the CTRL key until you see the No Company Open window, then release the CTRL key.
If QuickBooks still does not open:
If this solution does not resolve the issue, you can read discussions and post messages and questions relating to your issue on the Intuit QuickBooks Community site for free or you can contact a technical support agent for additional guidance. Fees may apply.